Droplet ejecting head

Abstract

A droplet ejecting head includes a first substrate, a nozzle plate, a second substrate, an annular symmetrically channel plate and an actuator device. The nozzle plate with a nozzle is disposed on a first surface of the first substrate. The second substrate with a liquid inlet is disposed over the first substrate. The annular symmetrically channel plate with a fluid channel is disposed between the first substrate and the second substrate so that a pressure chamber is formed between the second substrate and the annular symmetrically channel plate. The liquid to be ejected flows to the fluid channel from the liquid inlet and overflows to the pressure chamber from the fluid channel. The actuator device is disposed on the second substrate. The second substrate is deformed by the actuator device for changing volume of the pressure chamber, and then the liquid in the pressure chamber is ejected via the nozzle.

1. A droplet ejecting head, suitable for ejecting droplets of a liquid, the droplet ejecting head comprising:
 a first substrate, having a first surface and a second surface; 
 a nozzle plate, disposed on the first surface of the first substrate, and having at least a nozzle; 
 a second substrate, disposed over the second surface of the first substrate, the second substrate or the first substrate having at least a liquid inlet; 
 an annular symmetrically channel plate having a fluid channel, disposed between the first substrate and the second substrate, a pressure chamber being formed between the annular symmetrically channel plate and the second substrate, wherein the liquid flows to the fluid channel from the liquid inlet and overflows to the pressure chamber from the fluid channel; and 
 an actuator device, disposed on the second substrate, wherein the actuator device is adapted for driving the second substrate to be deformed. 
 
   
   
     2. The droplet ejecting head as claimed in  claim 1 , wherein the actuator device is disposed on the second substrate over the nozzle plate. 
   
   
     3. The droplet ejecting head as claimed in  claim 1 , wherein the annular symmetrically channel plate comprises:
 a first sub-channel plate, having at least a through hole; 
 a second sub-channel plate, disposed on the first sub-channel plate, and having at least a first annular hole and at least a second annular hole, wherein, part of the first annular hole and the second annular hole overlap the through hole of the first sub-channel plate; and 
 a third sub-channel plate, disposed on the second sub-channel plate, and the third sub-channel plate has at least a third annular hole, wherein part of the third annular hole is overlapped with the first annular hole. 
 
   
   
     4. The droplet ejecting head as claimed in  claim 3 , wherein the first sub-channel plate, the second sub-channel plate, and the third sub-channel plate are annular plates. 
   
   
     5. The droplet ejecting head as claimed in  claim 1 , wherein the nozzle plate comprises a nozzle layer, having the nozzle and a trench, wherein the nozzle passes through the nozzle layer, and the trench is disposed in an outer surface of the nozzle layer and encloses the nozzle, and the trench is separated from the nozzle with a distance. 
   
   
     6. The droplet ejecting head as claimed in  claim 5 , wherein the nozzle plate further comprises a filler filling in the trench, wherein the wetting angle of the surface of the filler is different from the wetting angle of the surface of the nozzle layer. 
   
   
     7. The droplet ejecting head as claimed in  claim 6 , wherein the material of the nozzle layer is a wettable material, and the material of the filler is a comparative anti-wettable material with the wettable material. 
   
   
     8. The droplet ejecting head as claimed in  claim 6 , wherein one of the material of the nozzle layer and the material of the filler is a wettable material, and another one of the material of the nozzle layer and the material of the filler is a comparative anti-wettable material with the wettable material. 
   
   
     9. The droplet ejecting head as claimed in  claim 5 , wherein the trench is an annular trench. 
   
   
     10. The droplet ejecting head as claimed in  claim 1 , wherein the nozzle of the nozzle plate is a tapered hole in full portion. 
   
   
     11. The droplet ejecting head as claimed in  claim 1 , wherein the actuator device is a piezoelectric material. 
   
   
     12. The droplet ejecting head as claimed in  claim 1 , wherein the nozzle plate has a plurality of nozzles. 
   
   
     13. The droplet ejecting head as claimed in  claim 12 , wherein the plurality of nozzles are arranged in an array.